Muffler.



PATENTED MAY 15, 1906. E. P. GRAY.

MUFFLER.

APPLICATION FILED JUNE 28, 1905.

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mitnzsses UNITED STATES" PATENT OFFICE.

EMMET P. GRAY, OF DETROIT, MICHIGAN, ASSIGNOR TO GRAY MANU-v FAOTURING'UOMPANY OF DETROIT, OF DETROIT. MICHIGAN, A COR- PORATION OF MICHIGAN.

MUFFLER.

Patented May I5, 1906.

Application filed June 28, 1906. Serial No- 267,360.

Detroit, in the county of Wayne and State of Michigan, have invented. a new and useful Mufl'ler, of which the following is a specification.

. the muffler on the line 1 1 of Fig. 2.

My invention relates to mufflers for the exhaust of gas, gasolene, and other explosive engines for automobiles and launches; and the objects of my improvements are to provide a simple and efficient muffler to deaden the noise caused by the exhaust of explosiveengines, to provide a muffler of this type whose outer surface cannot get hot' enough to burn olf the paint or other decorations thereon, and to provide a safetydevice in the nature of an automatic relief which, should unburned gases escape into the muffler and become ignited, would permit the escape of such gases without doing any damage.

I attain these objects-by the construction illustrated in the accompanying drawings, in which 1 a Figure l is a longitudinal cross-section of Fig. 2 is a view of the discharge end of the muflier. Fig. 3 is a cross-section on the line 3 3 of Fig. 1. Fig. 4 is a view of the middle baffie-pla'te. Fig. 5 is a detail showing the joint at the ends of the drums. l

Similar reference characters refer to like parts throughout theseveral views.

The exhaust of explosive-engines is usually very loud and sharp, so that mufiiers or other devices are employed to deaden the sound and'render-it less objectionable.

. able muflier is onethat is compact and that will not only reduce the sound of the exhaust to a minimum, but that will remain cool enough to retain paint or other decoration on its outer surface. I have found that a good sheet of asbestos secured. between two thin tubes of metal will prevent the passage of enough heat to burn the decorations onthe outside of the muflier. and thatasbestos is also a most desirable material for deadening the noise of the exhaust, being non-resonant andinert- Sheetsof mineral wool, made from blast-furnace slag, and other non-resonant substances that are poor conductors of heat may be used in place of the asbestos.

In the drawings three concentric cylinders held" in place by two heads are shown; but the sheet metal.

The desir-v number of the cylinders may be varied as desired. The outer cylinder is composed of the shells 1 and 2, of thin sheet metal, and the layer 3 of non-resonant non-conductive material, such as asbestos, between them. The second cylinder 4 is of but one thickness of The interior cylinder is, like the first, composed of the two shells 5 and 6 and the non-resonant layer 7. The heads 8 and 9 have offset shoulders to position these cylinders and are held together by the bolt or stem 10 and links 11, having nuts 12 on the outside of head 8. A pin 13 through the bolt 10 rests within a groove in the head 9, while the rounded ends of the links 11 are slidable in the head 8, and thus permit all parts to be well tightened. The asbestos or other fibrous material between the shells 1 and 2 and 5 and 6 projects beyond the ends of the shells,

.' so that when the nuts 12 are screwed up the projecting portions become upset. This has the double. purpose of forming a gas-tight joint between the cylinders and heads that will not be affected by heat and also decreasing the resonance of the heads by deadening their vibrations. (See Fig. 5.) I

Securedto the bolt 10 are the baflle-plates 14, I5, and 16. 5 Plates 14 and 16are somewhat smaller in diameter than the interior diameter of the shell 6 and have a row of holes near their outer edge,.as shown in Figs. 1 and 3, while the plate 15 is of the same diameter as. the interior diameter of the'shell 6 and has holes nearer its center, as shown in Fig. 4:. This arrangement forces the escaping gases to take a curved path through the interior cylinder, thus checking their speed. Near the outer end of the inner cylinder are rows of holes 17, through which the gases pass into the space between the inner and intermewhich holes are normally closed by-theplate V 21, held down by the spring 22 The tension of the spring is governed by the nut 23, which is held in place by the pin 24 passing through the slot25 in thebolt 10. In case unburned gases pass over into the muffler and there ignite the resultant pressure will be relieved by the plate 21 moving outward from over the openings 20.

The checking of the flow of the gases by forcing them to pass through the holes 17, 18, and 19 of the muffler causes a slight back pressure in the engine. To relieve this when full power is of more importance than absence of noise, I provide a lever 26, pivoted to the head 9, which lever has two pins 27, which engage in the groove 28 in the hub of the plate 21. By moving this lever the operator opens the holes 20, permitting the free escape of the exhaust of the engine.

The chief advantage of the layer of fibrous material in the inner cylinder is that it deadens the exhaust, while the layer in the outer cylinder prevents the heat of the gases from affecting the shell 1, which shell may therefore be painted or otherwise decorated without being in, danger of having the paint burned ofi'. It will be readily seen that the intermediate cylinder may be made like the other two or may be omitted, or the asbestos may be omitted from either the inner or outer cylinders. The exhaust-pipe of the engine connects to the center of the head 8 by means of the screw-threads 29 or in any other desirable manner.

Having now explained my improvements, what I claim as my invention, and desire to secure by Letters Patent, is I 1. A mufller for exhaust-gases, comprising a non-resonant cylinder, heads closing the ends of the same having assages for admitting the gases to said mu er and permitting their escape through the heads, and a plate to close passages in one of the heads.

2. A muflier for exhaust-gases, comprising a nonresonant cylinder, heads closing the ends of the same and having assages for admitting the gases to said cylinder and per mitting their escape, and means for closing the escape-openings, and means to operate said closing means.

3. A muffler for exhaust-gases, comprising a non-resonant cylinder, heads closing the ends of the same, one head having a passage for admitting the gases to said cylinder the other head having passages for permitting the escape of the gases from the cylinder, a plate for closing the escape-passages, and means to move said plate.

4. A muffler for gas-engine exhaust, comprising a plurality of concentric cylinders, heads for closing the ends of the same, said cylinders having ports connecting the spaces between the cylinders to the space within the inner cylinder, one of said heads having an opening to permit the entrance of the gases, the other head having openings connecting with the interior of the inner cylinder, outwardly-movable means for closing said openings, means to normally hold said movable means in closing position, and manually-operable means for causing the closing means to move outwardly.

5. In a mufiler, the combination of a plurality of shells, one outside of the other, heads for closing the ends of the shells, said heads having assages for admitting gases to the inner shel and for permitting the escape of the gases from the inner shell and from between the shells, and outwardly-movable means for closing the outlet-passages opening into the inner shell.

6. In a mufller, the combination of a shell, a head at each end of the shell, one of said head's having an opening to admit exhaustgases, a bolt passing through the other head, a pin engaging said head, means to secure the end of said bolt to the opposite head, a spring on the end of said bolt, a nut to regulate the tension of said spring, a plate pressed against the adjacent head by said spring, said head having openings for the escape of tllle exhaust-gases normally closed by the p ate. 7. In a :mufller, the combination of a plurality of shells, one without the other, heads to close the ends of the shells, a bolt to hold the heads in position, one of the heads having an opening to admit the exhaust gases, plates mounted on the bolt for the purpose of breaking the flow of the gases, and means to regulate the pressure of the gases in the inner shell.

8. In a muffler, the combination of a plurality of concentric cylinders, each comprising two thicknesses of sheet metal and a thlckness of fibrous non-resonant material between them, the fibrous material projecting beyond the ends of the metal shells, heads to close the ends of the cylinders, and means to draw the heads against the ends of the cylinders whereby the fibrous material will become upset to form tight joints between the ends of the cylinders and the heads.

9. In a mufller, the combination of a cylinder comprising two thicknesses of sheet metal and a thickness of non-combustible material between them, the fibrous material projecting beyond the ends of the metal shells, heads to close the ends of the cylinder, and means to draw the heads against the ends of the cylinder whereby the fibrous material will become upset to form tight joints between the ends of the cylinder and the heads.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

EMMET P. GRAY.

Witnesses: v

A. F. WrLeox, EDWARD N. PAGELSEN 

